Air cleaner for cooling device in driving system mounted on large size dump truck

ABSTRACT

An air cleaner for a cooling device in a driving system mounted on a large-size dump truck capable of separating and removing dust and rain water contained the air flow flowing in through an air intake portion from the air with a high efficiency. This air cleaner for cooling comprises a plurality of strata tubes (12) horizontally spanning between front and rear walls (1a, 1b) of a rectangular parallelepiped shape intake portion (1), a net pasted over the entire surface of the front of the intake portion, and a cover disposed in front of the net.

FIELD OF THE INVENTION

The present invention relates generally to a driving system coolingdevice mounted on an electrically powered contructional large size dumptruck. More specifically, invention relates to an air cleaner for thecooling device to be provided at an air intake for a cooling air and forseparating and removing dust and rain water from an intake air.

BACKGROUND OF THE INVENTION

An air cooling device for a driving system is mounted on an electricallypowered contructional large size dump truck which are used in a mine, aquarry and so forth. The cooling device has an air intake at the frontside of the vehicle. An air introduced through the air intake is fed toa generator, drive control device and a motor through an air passage forcooling the driving system.

As shown in FIGS. 8 and 9, the cooling device is provided with an aircleaner within an air intake 1 for separating a dust, such as a sand orso forth and rain water from the air for feeding only air to thedownstream. Conventionally, a louver array 6 is employed in the aircleaner. A plurality of louver arrays 6 are provided within the airintake 1 in such a manner that distances thereof are narrowed toward thedownstream side. Dust shoots 7 are provided between the narrowed ends ofthe louver arrays 6. The air introduced from the front side of thevehicle, i.e. from an air inlet side flows into spaces between thelouver arrays 6. The air flows through gaps in the louver arrays 6toward downstream. On the other hand, the dust and rain water are guidedinto the dust shoots 7 by the louver arrays 6 and fall down in the dustshoots 7. The dust and rain water are then externally discharged througha dust discharge valve 8.

In the driving system cooling device mounted in the electrically poweredcontructional large size dump truck, the conventional air cleaner tendsto permit fine particle dust and rain water to pass through the gaps inthe louver arrays together with the air to penetrate into the coolingdevice to reach the generator, the drive control device and motor of thedriving system to lower electrical insulation performance of the drivingsystem to cause damage.

On the other hand, as disclosed in Japanese Examined Patent Publication(Kokoku) 54-4106, there has been proposed a swirl flow type air cleanerformed by assembling a plurality of small diameter tubular bodies,preferably having a diameter less than or equal to 5 cm. However, sincethe air cleaner for the cooling device of the drive system of the largesize dump truck requires a huge capacity, especially as a machine formines, for low cost and long duration, a large number of small diametertubular bodies should be used for unacceptably loweringcost-performance. Furthermore, when such a large number is introducedinto the small diameter tubular bodies, air induction resistance becomessubstantially high, thus causing a lowering of a dust separationperformance.

Also, Japanese Unexamined Patent Publication (Kokai) No. 57-56657proposed a swirl flow type pre-cleaner of a thin panel type which isprovided on the top of an element type air cleaner. The disclosedcleaner has mutually opposite vane angles of a swirl type air inletwhich are provided at left and right side vanes to generate a gear typeswirling flow so as not to disturb laminar flow of the air. The shownarrangement is effective in separating relatively large particle sizesof dust. However, because of a substantially short axis distance of theswirl flow layer of the air, difficulty is encountered in separatingfine particle dust. Therefore, the structure must be followed by apleated type air filtering element at the subsequent filtering stage.Moreover, the pleated type air filtering element requires regularreplacement, thus increasing the cost. In addition, when a large amountof air is to be introduced, the intake air flow resistance becomessubstantially large to lower dust separation performance.

Japanese Examined Patent Publication No. 57-38302 proposed an aircleaner of the type in which a large spiral type air flow is generated.However, in the shown construction, a rain water eliminating cap maycause a lowering of installation density. On the other hand, when therain water eliminating cap is removed for higher installation density,bends at the air inlet and outlet may cause a swirling flow of the airat the air inlet and outlet of the element to affect uniform inductionof the air to lower the air induction efficiency.

SUMMARY OF THE INVENTION

In view of the problems as set forth above, it is an object of thepresent invention to provide an air cleaner for a drive system coolingdevice mounted a large size dump truck, which can separate and removedust and rain water contained in the air introduced through an airintake.

Another object of the present invention is to provide an air cleanerwhich is efficient in removing dust and rain water at a less expensivecost, and thus is suitable for application to a vehicle used in a minewhere high cost performance is required.

In order to accomplish the above-mentioned object, and in accordancewith a primary aspect of the invention, an air cleaner for a coolingdevice for drive system of a large size dump truck and disposed in acooling air intake portion for separating and removing dust and rainwater contained in an intake air, comprises a plurality of strata tubeshorizontally arranged within the air cleaner.

In order to accomplish the above-mentioned object, and in accordancewith another aspect of the invention, an air cleaner for a coolingdevice for drive system of a large size dump truck and disposed in acooling air intake portion for separating and removing dust and rainwater contained in an intake air, comprises a plurality of strata tubeshorizontally arranged within the air cleaner, a net attached to thefront face of an air intake and extending overall surface thereof, and acover arranged in front of the net.

Each strata tube may extend between a front end wall and a rear end wallof a rectangular parallelpiped shape box forming the air intake, andhave an air inlet opening at a front portion, a spiral screw type vanedisposed in the front half and fixed onto the inner periphery thereof, ahollow portion positioned at the intermediate portion, a smallerdiameter cylindrical pipe separately formed and inserted through andfixed on the read end wall for forming an air outlet opening, an annularclearance defined between the outer periphery of the smaller diameterpipe and the inner periphery thereof, and a discharge opening formedthrough the periphery at the corresponding position to the clearance.

In addition, the cover may be vertically elongated rectangularparallelepiped configuration and has a straightening vane of anessentially cross shaped cross section fixed to the inner side of thefront face thereof and extended to the front face of the net.

As set forth above, according to the present invention, the air cleanerfor a drive system in the large size dump truck includes strata tubesarranged horizontally. The air and so forth is introduced from theoutside into the strata tube to generate a swirl flow therein to carrythe dust and rain water toward the inner periphery of the strata tube.The dust and rain water thus carried are accumulated in a dust trap andexternally discharged through a dust discharge valve. With thisconstruction, the dust and rain water contained in the introducedcooling air can be separated and removed so that only air is fed to apassage pipe downstream of the air cleaner to flow into the coolingdevice to cool respective components of the drive system. By this, thedust and rain water can be separated and removed from the air with highefficiency to significantly reduce induction of the dust and rain waterto be introduced into the cooling device. Therefore, lowering of theelectrical insulation performance in the drive system can be preventedand possibility of failure can be eliminated to improve durability ofthe device.

In the preferred construction, each of individual stratum tube isprovided with a sufficiently large diameter for providing a satisfactoryair flow rate for effectively cooling various components of an electricdriving system for a constructional large size dump truck.

The above-mentioned and other objects, aspects and advantages of thepresent invention will become clear to those skilled in the art from thediscussion described and illustrated in connection with the accompanyingdrawings which illustrate preferred embodiments meeting with theprinciple of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side elevation showing one embodiment of thepresent invention, in which is illustrated an air intake in a drivesystem cooling device mounted on a large size dump truck;

FIGS. 2, 3 and 4 are respectively schematic front elevation, backelevation and plan view of the embodiment of FIG. 1;

FIG. 5 is a longitudinal section of a strata tube body employed in anair cleaner according to the present invention;

FIG. 6 is a schematic side elevation of a large size dump truck, onwhich the cooling device incorporating the air cleaner of the presentinvention is mounted;

FIG. 7 is a schematic plan view of the large size dump truck of FIG. 6;

FIG. 8 is a schematic horizontal transverse section showing theconventional air intake and the air cleaner;

FIG. 9 is a schematic side elevation of the conventional air intake andthe air cleaner of FIG. 8; and

FIG. 10 is an exploded perspective view of a cover employed in theembodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

One embodiment of the present invention will be discussed herebelow inconnection with the accompanying drawings (FIGS. 1 through 7 and 10).

An electric powering system for a large size dump truck is a system fordriving left and right rear wheels 10 by supplying power generated by agenerator 3 to drive motors 5 provided for the rear wheels 10. In suchsystem, the temperature of the drive system becomes high. Therefore, adevice for cooling the drive system is provided. Typically, an aircooling type cooling device is provided to blow an intake air to thedriving system by means of a blower 11.

In detail of the cooling device, as shown in FIGS. 6 and 7, an airintake 1 has a frontwardly directed inlet at the upper front portion ofthe vehicle. An air cleaner is provided within the air intake forreducing induction of dust, such as sand, and rain water. A passage tube2 is connected to the downstream side of the air intake 1. A blower 11powered by a generator 3 is disposed in the passage tube 2. The blower11 blows the intake air. The passage tube 2 is slitted into two branchesat downstream of the blower 11. One of the branches reaches the sidesurface of the generator 3 and opens thereto for air cooling thegenerator 3. On the other hand, the other branch reaches within a drivecontrol device 4 provided at the front upper portion of the vehicle andturned backward and further branched toward left and right torespectively reach the drive motors 5 provided for respective of theleft and right wheels 10 to open thereto to air cool the drive controldevice 4 and the motors 5.

Here, the air cleaner, according to the present invention, in the airintake 1 of the cooling will be discussed in connection with FIGS. 1 to4. The air intake 1 is a rectangular parallelepiped box shapedconfiguration, within which a plurality of strata tubes 12 are arrangedin substantially horizontal fashion. The tube is a registered trademarkof Donaldson Company, Inc., Minneapolis, Minn., U.S.A. The front andrear opening ends of the strata tubes 12 are respectively fixed to frontend wall 1a and a rear wall 1b. A net 14 is provided for coveringoverall area of the front face of the air intake. A cover 15 is furtherarranged at the front side of the net. The passage tube 2 follows therear end of the air intake 1. A duct trap 16 is arranged at the rearportion of the bottom of the air intake 1. A dust discharge valve 8 isprovided in the dust trap 16. With such construction, the air and soforth are introduced into the strata tubes 12 through the cover 15 andthe net 14 at the front face of the air intake 1. Within the stratatubes 12, the dust and rain water are separated from the air to flowonly air into the passage tube 2 following the rear end thereof. Thedust and rain water fall down in the air intake 1 to be accumulated inthe dust trap 16 and are then externally discharged through the dustdischarge valve 8.

Discussion will be given for a manner of separation of the air and soforth within the strata tube 12. The main body of the strata tube 12 hasa circular cross section. As shown in FIG. 5, the main body of thestrata tube 12 defines an air inlet opening 12a at the front portion. Aspiral screw type vane 17 is fixedly disposed in essentially the fronthalf of the main body of the strata tube 12. The main body of the stratatube 12 defines a hollow portion 12b at the intermediate portion. An airoutlet opening 12d is formed by inserting and fixing a smaller diametercylindrical pipe 18 through a read end wall 12c. The cylindrical pipe 18is extended into the hollow intermediate portion to define an annularclearance 12f between the inner peripheral wall surface 12e. A dischargeopening 19 is defined through the peripheral wall at the positioncorresponding to the annular clearance 12f. The air and so forth flowsinto the interior of the strata tube 12 through the inlet openingportion 12a and flows in a spiral fashion by the effect of the vane 17.Then, the dust and rain water are flown toward the inner peripheral wall12e due to centrifugal force and separated from the air. Therefore, onlyair flows into the cylindrical pipe 18 at the rear portion through theoutlet opening portion 12d. The dust and rain water thus corrected flowinto the clearance 12f at the read portion and discharged through thedischarge opening 19.

In the air cleaner of the present invention, it is preferred to providea device having the following construction at the air inlet 1. Namely,at the front face of the air inlet 1, the cover 15 is provided forpreventing the dust and rain water from directly penetrating into theair inlet 1. The cover 15 is formed into a rectangular parallelepipedconfiguration with opening at both sides and rear side. The opening atboth sides serve as the air inlet. The rear end opening is in directcommunication with the air intake 1 of the cooling device so that theair introduced into the cover 15 is fed into the air intake 1. In orderto prevent disturbance of air flow in the air intake 1, i.e. in aplurality of the strata tubes 12 of the air cleaner to lower air flowrate from being caused by the cover 15, a cross sectionally cross shapedstraightening plate 20 is disposed within the cover 15 and fixed at theinside of the front face thereof so as to divide the externallyintroduced air into four parts for orienting the flow. The oriented airflows into the air intake 1. Thus, air supply for the air intake, i.e.,the strata tubes 12 of the air cleaner can be done efficiently.

I claim:
 1. An air cleaner for a cooling device for a drive system of alarge size dump truck and disposed in a cooling air intake portion forseparating and removing dust and rain water contained in intake air,comprising:a plurality of strata tubes horizontally arranged within theair cleaner; a net attached to the front face of said air intake andextending over an entire surface thereof; and a cover arranged in frontof said net, said cover being in a vertically elongated rectangularparallelepiped configuration and having a straightening vane of anessentially cross-shaped cross-section fixed to the inner side of thefront face thereof and extending to the front face of said net.
 2. Anair cleaner for a cooling device for a drive system of a large size dumptruck and disposed in a cooling air intake portion for separating andremoving dust and rain water contained in intake air, comprising:aplurality of strata tubes horizontally arranged within the air cleaner,each strata tube extending between a front end wall and a rear end wallof a rectangular parallelpiped-shaped box forming said air intake, andhaving an air inlet opening at a front portion, a spiral screw type vanedisposed in the front half and fixed onto the inner periphery thereof, ahollow portion positioned at the intermediate portion, a smallerdiameter cylindrical pipe separately formed and inserted through andfixed on said rear end wall for forming an air outlet opening, anannular clearance defined between the outer periphery of said smallerdiameter pipe and the inner periphery thereof, and a discharge openingformed through the periphery at the corresponding position to saidclearance; a net attached to the front face of said air intake andextending over a surface thereof; and a cover arranged in front of saidnet.
 3. An air cooling device for an air cooling type driving system foran automotive vehicle, comprising:cooling air passage means defining anair inlet opening directed frontwardly and a cooling air passage fordirecting cooling air to a component of the driving system, said coolingair passage incorporating an air intake portion immediately followingsaid air inlet opening; an air cleaner disposed within said air intakeportion for removing dust, rain water and other impurities from intakeair, said air cleaner incorporating a plurality of axially arrangedstrata tubes defining a spiral flow portion, in whichimpurity-containing intake air flows in a spiral fashion, a straightflow portion following said spiral flow portion, and an air/impurityseparating portion following said straight portion; and a cover platearranged in front of said air inlet for blocking direct introduction ofair into said air intake portion through said air inlet, said coverplate cooperative with said air inlet opening to define at least onelaterally opening air induction mouth for introducing the air into saidair inlet opening.
 4. An air cooling device as set forth in claim 3,wherein said at least one laterally opening air induction mouthcomprises laterally opening air induction mouths defined at both lateralsides of said cover plate.
 5. An air cooling device as set forth inclaim 4, which further comprises a plate member blocking confluent flowof air introduced through both said laterally opening air inductionmouths and establishing straight air flow directed to said air inlet atboth sides thereof.